Common Errors in the Boot Sequence
Safe Mode
· Safe mode allows Windows 2000 and Windows 9x to load with only a minimal set of drivers.
· Safe mode provides just enough of an environment so that you can proceed to troubleshoot the OS using the built-in tools.
· On both a Windows 9x and a Windows 2000 system, you enter safe mode by pressing the F8 key during boot. You will be taken to a menu that allows you to access safe mode.
· In Windows 98, to enter Interactive Startup, and subsequently safe mode, press the Ctrl key while booting.
Common Windows Errors
- No operating system found
This means that the BIOS could not find the boot loader, which is Io.sys in Windows 9x and Ntldr in Windows 2000. Possible causes include:
o The boot loader is missing or corrupt.
o The hard disk was not detected by the BIOS.
o A floppy disk could be in the floppy drive, preventing a normal boot process.
o Physical installation of the hard disk was performed improperly.
o You have a boot sector virus.
- Error in Config.sys line xx
When a command in the Config.sys file cannot be processed properly, you might receive this error message, where xx indicates the actual line within the file that contains the error.
o Config.sys is a text file. To correct errors or modify the settings, use the Edit command, Notepad, or the Sysedit utility.
o To bypass a line in the Config.sys file, add a semicolon (;) or put the word Rem at the beginning of the line. This will cause the system to ignore the line.
- Bad or missing Command.com
The Command.com file cannot be located during the boot process. The Command.com file might have become corrupt or has moved.
o To correct the error, copy a new version of Command.com to the root directory from the Windows directory on a Windows 9x system, or from the first disk of a set of MS-DOS disks.
o Sys.com can be used to transfer a new copy of the Command.com (as well as Io.sys and Msdos.sys) file to the target drive.
- Himem.sys not loaded
If you receive this error message, the Himem.sys file is missing or corrupt. The Himem.sys file should be found in the Windows directory; if it’s not there, it might have been moved. If it is there, and the error message continues, it might be corrupt.
- Swap file
The swap file is the space on the hard disk used to store temporary data that will not fit into regular memory.
o A system that frequently hangs or freezes might indicate a problem with the swap file.
o To correct a damaged swap file in Windows 9x, delete the Win386.swp file and restart the system.
o To correct a damaged swap file in Windows 2000, simply restart the computer.
- Windows NT boot issues
Perhaps the most common Windows NT and Windows 2000/XP boot error message is “Could not find Ntldr.” To correct the error, consider the following:
o Ensure that there isn’t a disk in the floppy drive when the system boots.
o Check the physical installation of the hard disk.
o Verify that the BIOS detects the hard disk.
o The Ntldr file might be missing or corrupt.
- Dr. Watson
This is a troubleshooting utility that can be used to determine why a program or process is causing problems. In both Windows 2000 and Windows 9x, you can start Dr. Watson from a command prompt with the command drwatson.
- Failure to start graphical user interface (GUI)
One of the most common causes of no GUI is corrupted, or incorrectly configured display drivers. Another cause might be corrupt Windows files. To correct GUI errors:
o Try booting into Windows safe mode and replace the video drivers.
o Use the Windows NT or Windows 2000 Last Known Good Configuration option during bootup.
o Use the Windows 2000 Recovery Console.
- Windows protection error
This error is caused during startup by a problem with a device driver. The device driver with the problem may have been loaded through the system.ini file or by the registry. To correct the Windows protection error:
o Try booting Windows in safe mode.
o If in safe mode, update the device driver.
o Use the Windows NT or Windows 2000 Last Known Good Configuration option.
o Use the Windows 2000 Recovery Console.
o Edit the System.ini file to not load potentially problematic device drivers.
- A device referenced in System.ini, Win.ini, or the registry is not found
This error is caused by a driver being specified when its device is not present on the system. To correct the problem, remove the entry for the device.
o The System.ini and Win.ini files can be opened in any text editor like Notepad, or with the Sysedit utility.
o When you are troubleshooting an entry in the registry, you will need to use the appropriate registry editing tool: Regedit in Windows as well as Regedt32 in Windows NT or Windows 2000.
o Editing the registry is more safely accomplished by using the Control Panel utilities.
Recognizing and Solving Common Problems
Eliciting Problem Symptoms from Customers
· Gather information from users including any error messages, how frequently the error occurs, and what the exact error is.
· Wherever possible have the customer re-create the error.
· When gathering information from a customer, ensure that you ascertain whether there have been any recent changes to the computer system, including the adding or removing of files or programs. These changes can often be isolated as the cause of the problem.
Troubleshooting Windows-Specific Printing Problems
· Print Spool Is Stalled
o When a printer is configured to use print spooling, print jobs are first sent to the spooler, which saves the print job to the hard disk.
o Each pending print job is listed in the printer’s properties dialog box. The print job at the top is the one next in line for printing; cancel this print job if the spooler is stalled.
o If removing the print job does not get the print spooler going, on a Windows NT or Windows 2000/XP system you can stop and restart the print spooler service.
o To access the print spooler service, go to Control Panel, select the Administrative Tools icon, and then open the Services shortcut.
o Windows 9x does not use a print spooler service, so the system might need to be restarted to clear the print spooler.
o Sometimes it might appear that a print spooler has stalled when a large document or one with a large number of graphics is printed. Such a document can tie up resources and just slow the process down, but will work its way through the print spooler.
o The spooling process uses disk space to store print files. If there is not enough free space on your hard disk, you might find yourself unable to print large files irrespective of how much memory is installed in the system or in the printer.
· Incorrect or Incompatible Driver for the Printer
o If a printer fails or text is garbled in print jobs, update the printer driver.
o The latest printer drivers can be downloaded from the manufacturer’s Web site.
Other Common Problems
· General Protection Faults
o A General Protection Fault (GPF) occurs when a program attempts to start but the system detects a procedure in the program that could compromise another program or even the OS itself.
o A common cause of a GPF is when a program or device attempts to access a corrupted or unsupported device driver.
o When a GPF error does occur, your system might “blue screen.” This refers to the system halting with the display of a blue screen displaying white text outlining the cause of the problem. The text is often cryptic but can be used in conjunction with Microsoft’s support Web site.
· Illegal Operation
o An illegal operation is reported when a program tries to perform a function that the operating system is unable to carry out.
o Illegal operations are sometimes caused by a bug in the program itself.
o Sometimes an illegal operation error will be corrected after a reboot and sometimes a program might need to be reinstalled.
o The Microsoft support Web site (http://support.microsoft.com) contains detailed information on illegal operation errors and program troubleshooting.
· Invalid Working Directory
o An invalid working directory error can occur when a program’s directory has been moved, renamed, or deleted.
o To correct the error, you will need to put the directory back in its original location, or you might be able to correct the problem by editing the shortcut to the program, which has a field for the working directory.
o In some cases the program might need to be reinstalled.
· System Lockup
o Troubleshooting system lockups is particularly difficult because there are many different things that can cause the system to hang.
o Lockups can be caused by a hardware malfunction; for instance, if the system is hanging after new memory is added, the memory might not be correctly installed or configured.
o System lockups can also be caused by conflicting device drivers or failing programs.
o To recover from a system lockup, you can press Ctrl+Alt+Del to open the Close Program dialog box in Windows 9x.
o In Windows NT and Windows 2000/XP, the Task Manager can be used to shut down a frozen program. Press Ctrl+Alt+Del to invoke the Windows Security dialog box. From here you can access the Task Manager.
· Optional Device (Sound Card, Modem, Input) Will Not Function
o Device Manager is used to view the hardware devices detected by the system, and is the main utility used to view devices and device drivers in a Windows operating system.
o If the device is listed with a red X, it is not functioning or has been disabled. Alternatively, if there is a yellow circle with a black exclamation point, the device is not functioning correctly, which might mean there is a resource conflict or incorrect drivers being used.
o If a hardware device is not working, use Device Manager to locate any resource conflicts.
o Device Manager can be used to manually configure resources used by a hardware device and to update device drivers.
· Programs Don’t Install
o If you are trying to install a newer program onto an older system, the system’s resources might not meet the minimum requirements for that program. Refer to the program’s documentation to identify the minimum requirements.
o Program conflict Sometimes a program will fail to install if another program is running. For instance, a screen saver that starts during the install might cause the installation to fail. Similarly, a virus checker running in the background might do the same. When installing a program, it is suggested that you shut down all other programs.
o Installation media It is possible that the installation medium itself is corrupt; it might be a scratch on the installation CD or a damaged installation file on the floppy drive. If possible, try reinstalling the program with different media.
o Incorrect installation procedures Most modern programs install using the AutoRun feature and almost install themselves, but there are some that require a bit more work. Refer to the manufacturer’s installation procedures to verify that you have installed the program correctly.
· Program Will not Start or Load
o System resources If the program has just been installed, verify that the system has enough resources—memory, hard disk space, and processor speed—to run the program.
o Corrupted installation It might be that the program did not install successfully. Sometimes when a program fails to load, you will need to reinstall it to see if the problem is corrected.
o Virus If a program has been running and now fails to start, it might be that a virus has damaged the program’s files. Run a virus checker to see if there is a virus on the system.
o Incorrect shortcut path If you are unsuccessfully trying to start a program from the shortcut on the desktop, try starting it directly from the program’s main executable file. This file is located in the program’s directory. It might be that the path for the shortcut is just wrong.
o Deleted or moved files If a program used to work but now does not, it might mean that the program files have been deleted or moved. Use Windows Explorer to verify that the files are still where they need to be.
o Expired software If you were using trial software that has an expiration date, it might just be that the time has expired. Refer to the manufacturer’s Web site to confirm.
· Cannot Log on to Network (Option—NIC Not Functioning)
o Network card resources With the network card installed, verify that there are no resource conflicts and that it is recognized by the system. You can do this from within Device Manager.
o Verify LED Most modern network cards have an LED on them, referred to as the link light, that lights up when the card is making a connection to the network. If the LED is not lit, no connection is present. This could be caused either by a problem with the network card or some kind of connectivity issue elsewhere on the network.
o User name and password combination Network connectivity problems are sometimes as simple as the wrong password or user name being entered. Be sure they are correct before taking the troubleshooting procedure any farther.
o Network card drivers If you cannot connect to the network, you might need to verify that the correct network card drivers are being used. If in doubt, update the driver using Device Manager. Be sure to use the latest driver from the manufacturer’s Web site.
· Viruses and Virus Types
o Boot sector virus Boot sector viruses are targeted at the system’s boot sector; specifically, the boot sector virus changes the code of the master boot record (MBR). To remove a virus from the MBR, you can use the Fdisk command, using the following syntax: Fdisk /mbr. Many BIOSs now include a setting that can be used to protect the boot sector of the hard disk from virus infection. Given the destructive nature of a boot sector virus, if your BIOS has such a feature you should certainly enable it.
o Trojan horse program A Trojan horse program is so named because it disguises itself as something it isn’t. A Trojan horse program is often used to locate local passwords on the computer system, make the system vulnerable for a remote attack, or simply damage files on the local system.
o Executable One of the most dangerous types of virus is one embedded in an executable file because it can basically do anything, including mailing itself to everyone in your address book, or wiping out your system and any system yours is connected to. Executable viruses can be embedded in or launched from any executable file, not just those with .exe extensions. These include .bat, .com, and .cmd files. Viruses can also be embedded in or launched from script files which will be run by the operating system.
o Macro virus A macro virus is written in a macro language and placed within a macro, which can then be embedded in a document or spreadsheet.
· Virus Sources
o Floppy disks If a floppy disk has a virus on it, the virus can easily find its way to other systems. One way to prevent this is to use a virus checker with an autodetect feature that will check the disk when it is inserted.
o E-mail This has become one of the most common methods of distributing, and therefore contracting, viruses. Use a virus checker to ensure that no viruses are contained in e-mail attachments.
o Network When a computer system is connected to a network, especially the Internet, it opens up the potential for viruses to spread themselves around to the other computers on the network.
o Downloading software Many of us spend time on the Internet and at some point will download files onto our local computer. These files, many of which are executables, can be filled with viruses. Before installing any software that you have downloaded, be sure to check the files for viruses.
o How to Determine the Presence of a Virus Keep an eye out for unusual messages or window display boxes that appear on your screen. If these are not part of any program that you have installed they might be the work of a virus. Though most viruses are not overt, some will play sound files or music that will alert you to their presence. If you are looking for a program or a file and can’t find it, that could indicate a virus. Some viruses rename or delete files and program executables. When this happens, you will not be able to find them. If you suspect that this is happening, the best thing to do is run your virus checker right away. Some viruses will drain your system’s resources and the entire system will noticeably slow down. If you use a system resource utility to check the memory usage, you will find that it is extremely high considering the programs that are running on it. You might notice that the hard disk keeps filling and that overall performance, including loading programs, is noticeably slower. If you are looking through a computer system and notice new files or programs that shouldn’t be there, they could be virus programs or the by-product of a virus infection. To verify this, refer to the Web site of your virus software manufacturer.
